1. Field of the Invention
The present invention relates to a waveguide probe and more particularly, to an H-plane hermetically sealed waveguide probe.
2. Description of the Prior Art
Waveguides are known in the art for conducting relatively high frequency microwave signals, typically having wavelengths less than 10 cm. Such waveguides are generally formed as rectangular hollow structures with conducting walls which support transverse electric and magnetic (TEM) waves. In order to connect microwave signals from such waveguides to a microwave circuit, waveguide to microstrip adapters, known as microstrip probes, are known. Such microstrip probes generally include a conductor formed on one side of a dielectric substrate with a ground plane formed on the opposing side of the substrate. In order to couple the microwave energy from the waveguide to the microstrip probe, the microstrip conductor is extended into the center portion of the waveguide and aligned with the E-field, defining an E-field probe.
Such probes are used with microwave circuits formed in modular packages defining microwave modules. However, the physical and isolation constraints of the module may not be amendable to the use of an E-field probe. More particularly, such modules require good isolation between adjacent signal ports. The isolation between ports prevents undesired frequency products from leaking into adjacent ports. Normally relatively large physical distances are used to separate the ports such that any signal leaking from a port will be significantly attenuated before it reaches an adjacent port. However, large physical separation between ports is not always possible, for example, in space applications where such modules are relatively compact. In such applications the physical lay out of the module may prevent coupling of the microwave energy in the same direction of the E-field from the input waveguide. Thus, there is a need for a waveguide probe which allows coupling of the microwave signal in the direction of the H-plane.